The present invention relates to a combine harvester with a threshing unit and a driver assistance system for controlling the threshing unit and a sensor system for ascertaining at least a portion of the current harvesting-process state.
Combine harvesters are used for mowing and the threshing of grain. The threshing is carried out with a threshing unit, which obtains grain from the crop picked up by the combine harvester by a header. The grain, after threshing, separation and subsequent cleaning, is fed to a grain tank. The chaff and the straw, for example, remain as further components of the crop and are either spread onto the field or, in the case of straw, set down as swath, e.g., to be subsequently picked up by a baler. Here and in the following, the term “crop” is intended to mean the entirety of the crop stream picked up by the threshing unit, i.e., including the grains that have not yet been obtained as grain from the crop, and the grains that may remain in the crop stream as a loss and that may be deposited with the straw.
In the threshing unit, the grain is rubbed, i.e., threshed, out of the straw by a processing, which is rolling, in principle, and is separated from the remaining crop stream, so that it is fed directly to the cleaning system. The remaining crop stream is then fed to the separation area in which the remaining grain is separated from the crop stream, e.g., by a straw-walker system, and is then likewise fed to the cleaning system.
There is an entire series of criteria on the basis of which the quality of the threshing process is evaluated. First, preferably all the grain should be removed from the crop stream and fed to the grain tank, specifically, with as few broken kernels as possible and with a minimal portion of material other than grain. Secondly, the straw should not be damaged and, e.g., cut up, to such an extent that subsequent utilization is adversely affected. Third, the time required for the processing of a field should be short and the associated fuel consumption should be kept as low as possible. Further quality criteria are conceivable. Depending on the overall situation, in particular on the particular basic economic conditions, different quality criteria are paramount, which criteria collectively form a harvesting-process strategy for carrying out the harvesting process.
In order for the aforementioned quality criteria to be met, the threshing unit must be controlled in a certain manner, wherein this manner depends not only on the special quality criteria, but also on different conditions of the environment, of the combine harvester and, in particular, of the threshing unit itself, and on the type and composition of the crop. The prioritization of one quality criterion is usually a disadvantage for another quality criterion.
DE 10 2009 009 767 A1 discloses a combine harvester comprising a driver assistance system that measures different variables (e.g., drum speed, concave width, grain losses) on the combine harvester and checks the measured variables to determine whether they pass into a critical value range or exceed or undershoot critical limit values. If this situation occurs, the driver assistance system interactively communicates with the driver by proposing, to the driver, measures to take during the control of the threshing unit that are intended for moving out of the critical value range. The driver can then accept or reject these proposals, wherein, in a subsequent step, alternative proposals may be made to the driver, or the driver can specify the proposed measures more precisely by an entry. For the purpose of measuring the aforementioned variables, the driver assistance system is equipped with a sensor system comprising different sensors for recording different types of losses, such as threshing losses, separation losses, cleaning losses, or the like.
A challenge for implementing the driver assistance system is that different combine harvesters, due to the equipment package thereof, can have different sensor systems, which are usually complex, and the particular sensor system may also expand or be reduced over the course of a product life cycle of the combine harvester. In addition, individual sensors of the sensor system can fail due to wear. The aforementioned aspects can complicate the production of the combine harvester, and the latter aspect can adversely affect the operation of the combine harvester.